If I am understanding correctly, there appears to have need no reason to close the bypass at all. Line and load side switches could have been closed and then the breaker if at a substation. Sounds like it may be a single phase line and regulator down line from the station except that there...
Well, they can easily be moved if the line side blades/switches are closed from a powered bus. Also to add one step to crshears well detailed routine, I also turn the control power off after running it to neutral and verifying the position indicator and neutral light prior to bypassing. One...
Another advantage to individual circuit regulators is the ability to keep a spare unit or units on hand for quick replacement and.....only one circuit affected at a time.
I think the standards require a minimum fault rating of 25 times the base load current raring of the regulator. Don't have...
Disadvantages? Unless you are the utility that owns the line, you will have to deal with the right of way restrictions in place, an may still even if you are the utility. Most utilities that I am aware of here in the states do not allow placement of anything permanent, other than possibly a...
You have gotten several reputable references right here. You just need to heed the advice as you are not grasping the basics with this. These guys are correct....and to quote DRWeig.....'nuff said. Otherwise, you really need to hit the books!
Alan
This is in a substation that feeds outgoing utility distribution feeders with all combinations of loads. Zero sequence removal is done with the settings. I was reminded today that for 2 to 3 months the transformer had between 15 and 20+ MVA on it while another station was down for maintenance...
No I am not completely sure. But for now the transformer mfg. stills owns it since it is still under extended warranty. The mfg. has blessed its return to service, but I want to make sure I have data the next time.....if and when! BTW it is ONAF.
Thanks!!!
Alan
norcalnewb,
We did use it prior to commissioning and have checked since. Have not input measured values though. Plan for now is to replace the relay and do another complete wiring check and testing.
Thanks
Alan
dpc....agree that there are many wrongs and only one right. To clarify, the system faults I referred to are on the distribution system fed by the transformer, so they are through faults.
pwrtran....cabinet heaters are working and all is clean and dry. Most recent trip was on a beautiful dry...
Thanks to all so far. I made myself a promise in about 2009 never to install a critical relay unless it had memory for an event/fault history with vector data. This unit has been loaded to approx. 5000 kW during its life so far. We have had numerous system disturbances with breaker trips to...
Looking forward to input!
In summer 2008 we commissioned a 20/27/33 MVA, 115-25 kV, Delta-Wye substation transformer. Subsequently we have had 3 differential trip events on the unit and have yet to determine the cause. Except for thes ethree events the transformer has otherwise been in...
